Brennan, A. (1995). The ethics of the environment. Dartmouth.
Lua i Stíl Chicago (17ú heag.)Brennan, Andrew. The Ethics of the Environment. Aldershot, Hants, England ; Brookfield, Vt.: Dartmouth, 1995.
Lua MLA (9ú heag.)Brennan, Andrew. The Ethics of the Environment. Dartmouth, 1995.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.